Disable pypy jobs in ironic-python-agent

Due to https://github.com/eventlet/eventlet/pull/84 pypy tests are
timing out for IPA after 40 minutes. Disabling them for now so we don't
have to wait 40m+ for check/gate testing.

This should be re-enabled once the upstream fixes to eventlet are merged
and

Change-Id: Ie202367fbac7f627ea4f1094b71fdcbb66b0cb08
Merge "Disable pypy jobs in ironic-python-agent"